FIG. 3 illustrates in part a known coin processing machine 10. The coin processing machine 10 has proven in practice to be a reliable and durable device that accurately sorts, counts, or verifies coins at high speed.
Coin processing machine 10 has a rotatable turntable 12 mounted in stationary plate 14. Turntable 12 has an upper coin support surface 16 flush with upper coin support surface 18 of plate 14.
Stationary raking finger 20 and stationary guide finger 22 are mounted on plate 14. Raking finger 20 and guide finger 22 define a first opening 24 that receives a singulated stream of coins from turntable 12. A raised peripheral wall (not shown) mounted to plate 14 partially surrounds the turntable 12 and has an opening aligned with opening 24 to enable coins leaving turntable 14 to move between fingers 20 and 22.
A belt drive 27 has a belt run 29 located above plate 14. The belt run 29 engages coins entering opening 24 and accelerates the coins towards coin through-slot 26 formed in plate 14. The belt drive 27 spaces the coins apart as the coins move towards slot 26 as is described in my U.S. patent application Ser. No. 11/032,718 filed Jan. 11, 2005, which application is incorporated by reference as if fully set forth herein. The belt run 29 urges the coins towards a first, planar guide surface 28 of guide finger 22 (that is, the belt run 29 does not extend parallel with guide surface 28 but extends towards surface 28 as the belt run extends towards slot 26).
Sensors 30 carried in plate 14 are located between opening 24 and slot 26. Sensors 30 are also described in my '718 application and so are not described in detail here. Each sensor 30 is associated with a different diameter coin and is spaced a predetermined distance from guide surface 28. The sensors are arranged to first detect the largest diameter coin (in the illustrated embodiment a US half-dollar piece) and then detect each succeeding smaller-diameter coin as a coin in contact with guide surface 28 passes sensors 30. The sensors 30 are connected to a controller (not shown) that records the denomination of each coin passing the sensors 30 and maintains a running count of the value of the coins discharged from turntable 12.
In operation, a stream of coins is discharged from the turntable 12 and move through opening 24. Opening 24 is sized such that the largest diameter coin of the coin or currency used with the machine is closely received within the opening. The illustrated opening 24 is sized to closely receive a US half-dollar coin. Opening 24 is preferably approximately 0.005 inches to 0.05 inches larger than the diameter of the half-dollar coin.
Larger-diameter coins such as half-dollar coins or quarter-dollar coins contact nose 32 of guide finger 22 as the coin passes through opening 24. The belt rotates or pivots the coin about opening 24 as the coin is driven along guide finger 22 to slot 26. This assures that the edge of the coin maintains contact with guide surface 28 as the coin moves along guide finger 22. The coin is properly aligned against guide surface 28 as the coin passes sensors 30 for accurate discrimination and counting of the coin.
Smaller-diameter coins such as US-currency nickels, dimes, and pennies may pass through opening 24 without contacting raking finger 20 or guide finger 22. The belt urges a smaller-diameter coin towards guide surface 28 as the coin moves towards slot 26. Even before contacting guide surface 28, the coin is sufficiently close to surface 28 that the coin does not pass over the sensors 30 associated with the larger diameter coins. The coin contacts and abuts guide surface 28 before passing over the sensor 30 corresponding to its coin denomination for accurate discrimination and counting of the coin.
It has been observed, however, that sensors 30 may miscount some smaller-diameter coins if the coins are wet or oily. It is believed that the moisture or oil acts as a lubricant that reduces friction between the belt and the coin. The reduced friction is believed to prevent the belt from reliably moving smaller-diameter coins that enter the opening 24 while relatively close to the raking finger 20 against the guide surface 28 before reaching the sensors 30. Such smaller-diameter coins may remain away from guide surface 28 and pass over the upstream sensors intended to sense only larger-diameter coins. As a result, the coin is mistakenly sensed and counted as a larger denomination coin.
Thus there is a need to improve the coin machine 10 and its equivalents for more accurate processing of wet or oily coins.